The watershed comes amid an overall decline in abortion, a choice that remains politically charged in the United States, sparking a fiery exchange in the final debate between presidential nominees Hillary Clinton and Donald Trump.

When the two medications used to induce abortion won U.S. approval 16 years ago, the method was expected to quickly overtake the surgical option, as it has in much of Europe. But U.S. abortion opponents persuaded lawmakers in many states to put restrictions on their use.

Although many limitations remain, innovative dispensing efforts in some states, restricted access to surgical abortions in others and greater awareness boosted medication abortions to 43 percent of pregnancy terminations at Planned Parenthood clinics, the nation’s single largest provider, in 2014, up from 35 percent in 2010, according to previously unreported figures from the nonprofit.

The national rate is likely even higher now because of new federal prescribing guidelines that took effect in March. In three states most impacted by that change – Ohio, Texas and North Dakota – demand for medication abortions tripled in the last several months to as much as 30 percent of all procedures in some clinics, according to data gathered by Reuters from clinics, state health departments and Planned Parenthood affiliates.